Heat oven to 350°F. Fit piecrust into 9-inch pie plate; flute edges. Prick crust all over with fork; line with foil; fill with dried beans or pie weights. Bake in 350°F oven 10 minutes. Let stand until cool enough to handle. Remove foil.
In saucepan, heat milk, 1/2 cup cream and 1/2 cup sugar to bare simmer. Remove from heat; add chopped chocolate.
In medium bowl, stir together eggs and cornstarch until a paste. Whisk in yolks. Gradually whisk in chocolate mixture. Stir in the vanilla. Strain into prebaked crust.
Bake in 350°F oven 35 minutes or until center is set. Transfer to wire rack; let cool completely.
In medium bowl, beat remaining 1-1/2 cups cream and 2 tablespoons sugar until medium-stiff peaks form. Spread over top of pie. Garnish with chocolate curls, if desired.
